1. Technical Field
The present disclosure relates to a photographic device, and more particularly to a photographic device having auxiliary light sources.
2. Related Art
Through monitoring photographic technology, motions in the monitored environment may be photographed and recorded, and such photographic technology may effectively replace conventional security personnel. The monitoring photographing may combine an optical recognition technology with an alarm system so that an alarm signal is emitted when an abnormal condition occurs in the monitored environment, which has become a main passive security mechanism at present.
The majority of apparatuses employing the monitoring photographic technology are monitoring cameras which may be sorted into an indoor type and an outdoor type according to the environment where the monitoring camera is set. In addition to a required waterproof and dustproof function since the outdoor-type monitoring camera is disposed outdoors, the outdoor-type monitoring camera is further required to have a night vision function since 24-hour photographing is required outdoors. At present, the outdoor-type monitoring camera uses an infrared light source as an auxiliary light source during photographing at night.
The outdoor-type monitoring camera including a body, and electronic parts such as a lens and an image sensor are used for taking a photograph and infrared Light Emitting Diodes (LED) surrounding the lens are disposed in the body. A front cover is combined on a front end of the body, and transparent glass is disposed on the front cover, so that external light passes through the transparent glass and enters the lens, or light emitted by the infrared LED passes through the transparent glass and illuminates a photographic area. When the light emitted by the infrared LED passes through the transparent glass, the light is theoretically refracted merely since the transparent glass and the air are different media. However, in fact, partial light is reflected on a top surface or a bottom surface of the transparent glass since the top surface and the bottom surface of the transparent glass both are smooth surfaces. The reflected light may enter the lens, and cause the halo phenomenon or the ghost image phenomenon on the formed image, so that the image is blurred or unrecognizable.
In order to avoid the halo phenomenon or the ghost image phenomenon due to the illumination of the infrared light source on the transparent glass, in the prior art, a circular hole is cut at a position on the transparent glass corresponding to the lens, and a shielding component is disposed at the circular hole, in which the shielding component is cylinder-shaped. One end of the shielding component assembled at the circular hole of the transparent glass and the other end sleeved on the lens, so that the shielding component is located between the infrared LED and the lens (referring to Taiwan Patent Publication No. M294796). Since the shielding component protrudes from the transparent glass and is sleeved on the lens, even if the light generated by the infrared light source is reflected when passing through the smooth top surface or the smooth bottom surface of the transparent glass, the reflected light cannot enter the lens, thereby effectively preventing the halo phenomenon or the ghost image phenomenon.
However, in order to enable the outdoor-type monitoring camera to be waterproof and dustproof (for example, the highest level IP68 in International Industrial Waterproof Standard), the junction of the combination components such as the body, the front cover and the transparent glass disposed on the front cover is required to be sealed by waterproof materials such as a sealing ring. In addition, in order to prevent the reflected light of the infrared light source from entering the lens, the shielding component needs to include multiple parts and the transparent glass of the front cover needs to be cut and to be remanufactured, and in order to be waterproof and dustproof, the shielding component needs to be further disposed by waterproof materials such as a sealing ring. Hence, not only the cost is increased, but also the waterproof and dustproof effect is not desirable due to the additional multiple parts and complex remanufacturing and assembling procedures of making the waterproof and dustproof monitoring camera.